Pavement cutting and water and cutting pickup apparatus

ABSTRACT

A concrete or other pavement planing, texturing and grooving machine embodying a vacuum pickup assembly located outside the perimeter of the groove-producing cutters, the cuttings being flushed away by water issuing from nozzles at the work region and producing a slurry with the cuttings, which slurry is sucked into the pickup assembly aided by ambient air also sucked from the pavement region into its confines. The air and water slurry mixture is drawn into a separating tank where the water slurry drops to the lower tank portion, the air being exhausted to atmosphere. The water slurry is pumped to a settling tank where the cuttings and water are separated and the clean water repumped to the nozzles located at the cutters.

United States Patent hwemol' Theodore Burnett Danielsson et al 15/320 X oransmcalit 1,752,965 4 1930 Robertson 51/176 [2|] App N 812,994 3,119,602 1/1964 Johnson 299 81 x 1 Filed Apr-3,1969 3,407,005 10/1968 Simmset al 299/39 [45] Patented Sept. 28, 1971 P [73] Assignee Christensen Diamond Products Company "mary Exammer El 'nest Purser San Lake City Utah AttorneyBernard Krlegel [54] PAVEMENT CUTTING AND WATER AND ABSTRAQT: A concrete or other pavement planing, texturing CUTTING PICKUP APPARATUS and groov1n g machmeembodymg a vacuum pickup assembly 20 Claims, 4 Drawing Figs located outside the perlmeter of the groove-pi oducmg cutters, the cuttmgs being flushed away by water 1ssu1ng from nozzles [52] U.S. Cl 299/39, at the work region and producing a Shmy with the cuttings,

15/320, 51/176 which slurry is sucked into the pickup assembly aided by am- [Sl] lnLCl E0lc 23/09 hieht air also sucked f the pavement region i i [50] Fleld of Search 299/39, 41, fi The ahd water slurry mixture is drawn into a Swarm- 15/320 ing tank where the water slurry drops to the lower tank portion, the air bein exhausted to atmos here. The water slurr [56] References Clted is pumped to a se ttling tank where the cuttings and water are UNITED STATES PATENTS separated and the clean water repumped to the nozzles 1,752,882 4/1930 Boutwell 15/320 located at the cutters.

a4 7 O i i "1 52 f 0 V a la 7/ 64 50 (/0 l2 3/ aa 3 33 PATENTEU was 191:

SHEET 1 BF 2 Q I/vz/E/v 7-02 71/500025 302N577- mama; 35m 12m SHEET 2 [IF 2 INVENTO/Q 11/500025 Bug v r flm/ W PAVEMENT CUTTING AND WATER AND CUTTING PICKUP APPARATUS The present invention relates to apparatus for cutting concrete and similar pavement surfaces, and more particularly to such apparatus in conjunction with auxiliary apparatus for removing cuttings and flushing liquids from the region where the cutting operation is being performed.

Apparatus is used for planing, texturing or grooving pavement surfaces, the cuttings being flushed from the work region by water, which also cools the cutters and maintains them in a clean condition. One such machine is disclosed in US. Pat. No. 3,414,327, in which a gang of diamond-milling cutters are rotated to cut the concrete or similar surface and produce parallel grooves therein. Other types of apparatus employ a gang of closely spaced rotatable saw blades which have rim portions provided with diamond-cutting elements for cutting into the concrete or other surface, the cuttings also being flushed from the work region by water, that also maintains the saw blades in a clean and cool condition.

The flushing of the cuttings with water, or the like, creates many problems. If the pavement-cutting apparatus is being used to perform a planing or grooving action on a single traffic lane of a multiple lane highway, the flushing of the cuttings from the grooved lane in the direction of its slope or inclination to the shoulder at the side of the roadway requires that the additional traffic lanes be closed to permit such washing action to occur. If the cuttings were left on the pavement, they would create a skid hazard when wet, and, when dry, a dust hazard. In addition, where the traffic lane has grooves formed in it, the cuttings may cake into the grooves and thereby reduce the nonskid effectiveness of the grooved and ribbed highway lane. Under conditions in which the cuttings were hosed toward the roadway shoulder, contamination of adjacent local streams and lakes by the slurry also becomes a problem in some areas, raising conservation and legal questions.

Prior attempts at removing the water and cuttings have not been successful. Commercial street sweepers and ordinary vacuum devices have been unable to pick up liquids, solids, and air together. Commercial positive displacement pumps are capable of picking up the liquids, or the air and liquid together, but they cannot effectively handle the abrasive solid cuttings without severe wear of valves, cylinders, piston rings and other parts with which such abrasives come in contact. Commercial air vacuum units will pick up solids entrained in an airstream, but separating filters become clogged readily. Where the solids are mixed with water, the prior vacuum units are incapable of sucking in the needed air.

By virtue of the present invention, the slurry of water and cuttings is removed from the pavement surface as it is formed. lt is stored for later disposal at an appropriate location removed from the roadway. A tubular vacuum device is disposed both forwardly and rearwardly of the rotatable cutter members, as well as outwardly of their end portions. Water is discharged against the cutters and the work region to clean and cool the cutters and flush the cuttings from the work region. The water mixes with the cuttings to form a slurry which is pulled by a vacuum device into and through the tubular device. The tubular device may be enclosed partially in a housing or shroud in such manner that air is drawn at the pavement surface from regions forwardly and rearwardly of the cutters, as well as from their end portions, this air facilitating the lifting of the slurry from the pavement and its entry into the tubular device, from where it is drawn by a vacuum pump to a suitable location. Preferably, the air and slurry mixture is drawn into a separating tank, where the slurry can settle to' the bottom, the air being withdrawn by a vacuum pump for discharge to the atmosphere. When the separating tank fills partially to any desired level, the slurry is pumped to a standing tank truck where the water and cuttings are separated, the clean water then being redelivered to the cutting region for reuse in cleaning and cooling the cutters and for cleaning the work region of cuttings.

Through use of the apparatus, desirable objectives are achieved. One of these objectives is to permit reuse of the flushing water, which is of importance particularly where water is scarce.

Another object of the invention is to provide an apparatus for picking up substantially all of the cuttings and the water slurry from the immediate area of the cutters during the cutting operation, so as to leave a clean and safe surface, without disturbing adjacent traffic lanes.

A further object of the invention is to provide an apparatus that permits the slurry to be stored for later disposal at a desirable and convenient location.

Yet another object of the invention is to provide an apparatus that picks up the water and heavier-than-water cuttings together, and in which an airflow is employed to scour and to raise the slurry off the pavement for more effective entry into the vacuum pickup device.

Yet a further object of the invention is to insure the removal of the cuttings and water slurry from the pavement surface, eliminating dust problems after the pavement surface has dried.

Still a further object of the invention is to provide an apparatus that eliminates the flow of slurries onto adjacent lanes of traffic, thereby eliminating the dangers of skid. Moreover, the removal of the slurries, where the pavement surface is being grooved, insures that the grooves are not clogged with cuttings, which would reduce the skid-resistant properties of the pavement surface.

Another object of the invention is to provide an apparatus that effects the removal of the cuttings and liquid slurry from the work region and for retaining the slurry until proper disposal can be effected, thereby preventing the contamination by the slurry of local streams and lakes, which could occur in the event of the slurry being flushed onto roadway shoulders.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying the forming part of the present specification. it will now be described in detail, for the purpose of illustrating the general principles of the invention; but is is to be understood that such detailed description is not to be taken in a limiting sense.

Referring to the drawings:

H6. 1 is a side elevational view of a pavement-cutting apparatus embodying the invention;

FIG. 2 is a top plan view of the apparatus disclosed in FIG.

FIG. 3 is an enlarged vertical section taken along the line 3-3 on H6. 2; and

FIG. 4 is an enlarged vertical section taken along the line 44 on FIG. 3.

The embodiment of the invention illustrated in the drawings includes, by way of example, the particular pavement-cutting apparatus disclosed and described in detail in US. Pat. No. 3,414,327. It is to be understood, however, that other pave ment-cutting apparatus can be used in connection with the cuttings and water slurry removal features of the invention. Such apparatus includes a main frame 10 having front and rear pavement-engaging wheels 1], 12. The specific apparatus illustrated includes a sensing assembly 13 extending forwardly of the steerable front wheels ll so as to automatically adjust the depth of cut by the rotating cutting assembly 14, which is appropriately mounted on the frame of the apparatus between the front and rear wheels.

As disclosed most clearly in H63. 3 and 4. the specific cutting assembly disclosed, by way of example only, consists of a diamond-milling cutter arbor gang that includes a cutter shaft 15 extending transversely of the apparatus on which milling cutters 16 are suitably secured, these cutters having parallel circular ribs 17, the circular ribs and the intervening spaces having diamond-cutting elements not shown) mounted therein for effecting a cutting action on the pavement surface, and, more specifically, for producing parallel grooves 18 defined by parallel ribs 19 in the pavement itself. The specific milling cutters form no part of the present invention. They may be of the type illustrated in us. Pat. No. 3,306,669. The shaft is supported by the frame 10 of the apparatus through the medium of suitable bearings 20, and the entire cutter arbor assembly is rotated by a power mechanism (not disclosed) that rotates the cutter assembly through intermeshing gear 21, 22.

The vehicle is self-propelled. As it moves along the roadway or highway lane at the desired speed, the cutters 16 are rotated to produce the parallel grooves in the pavement surface. The cuttings from the concrete or other type of pavement are flushed from the work region, the cutters themselves being cleaned and cooled by water which flows from a'suitable supply source, such as an adjacent tank truck T (FIG. 2), through a suitable hose 23 to a water inlet pipe 24 carried by the apparatus, this inlet pipe communicating directly or indirectly, as disclosed and described in US. Pat. No. 3,414,327, with a water manifold 25 extending parallel to and along the length of the cutter, the water discharging from the manifold through a plurality of spaced nozzles or outlets 26 onto the rotating cutters 16 (FIG. 4). A generally cylindrical water guard 27 extends arcuately around the cutters, with the ends 28 of the water guard in spaced relation to the pavement surface S, the water being directed around the cylindrical guard to cool and clean the cutters and to carry the cuttings from the work region primarily in a direction forwardly of the apparatus.

For the purpose of removing the cuttings and water from the work region, a vacuum pickup assembly 30 is towed behind the main portion of the cutting apparatus by means of tow bars 31 which are pin-connected to the forward end of a trailer frame 32 having roadway-engaging forward and rearward wheels 33. Mounted on the trailer frame is a separating tank 34, a suction pump 35, preferably of the positive displacement type, which has its suction line 36 connected to the upper central portion of the separator tank, and its discharge line 37 exhausting to the atmosphere. This pump is rotated by a suitable engine 38, mounted on the frame 32, through a belt and pulley transmission 39.

A slurry-handling pump 40, preferably of the centrifugal type, is also mounted on the trailer frame 32, being driven by a suitable engine 41 supported on the frame, a suction line 42 being connected to the bottom of the separator tank 34 and running to the inlet of the centrifugal pump, a valve 43 being mounted in the suction line which is opened when slurry in the separator tank is to be withdrawn by the centrifugal pump and discharged through a discharge line 44 connected to the centrifugal pump, which preferably runs to a settling tank 45 forming part of the tank of the tank truck T located adjacent to the cutting and pickup apparatus. The tank of this truck is divided into two compartments 45, 46 by a vertical overflow weir 47, so that the cuttings settle to the lower portion of the settling tank 45 and the clean water overflows into the forward compartment 56 of the tank truck, from where a water pump 48 pumps it back to the water inlet 24 of the apparatus, which, as stated above, communicates directly or indirectly with the water manifold 25.

The separating tank 34 to which suction is applied by the positive displacement pump 35 is connected to a vacuum pickup device disposed around, but in closely spaced relation to, the milling cutters 16 and spaced a small distance above the pavement surface S. This pickup device includes a suction tube construction 50 comprising tubular portions 51, 52 parallel to and disposed forwardly and rearwardly of the cutter assembly, which communicate with and are connected to end tubular portions 53 disposed outwardly of the cutters 16. The forward, rearward, and end tubular portions are welded, or otherwise secured, to each other to provide a rectangular tubular device 50, the lower ends having bottom slots 54 extending throughout their length and through which the mixture of cuttings, water and ambient air will pass. This rectangular tubular device is suitably supported from the frame 10 of the apparatus, as by means of brackets 55 attached to the frame and also to attachment rings 56, each of which is welded to a vertical conically shaped tube 57, which is, in turn, welded to the central portion of the end tube section 53. The brackets 56 are so constructed and arranged as to dispose the rear hollow tube 52 at a slightly lower elevation than the forward tube 51, in view of the fact that the cut surface of the pavement is at a lower elevation than the forward surface. in other words, since the level of the pavement surface behind the cutters 16 is lower than the pavement surface in front of the cutters, the rectangular tube device is tilted upwardly in the direction of travel of the apparatus by several degrees, the angle of inclina tion V being indicated on H6. 4 of the drawings. By way of example, this angle can be of the order of from about two to four degrees. In atypical case, the bottom of the tubes 51, 52, 53 at which the mixture of slurry and air enters through the slots 54 will be disposed about inch above the pavement surface S.

In the event that ambient air is to be inhibited from entering the pickup device within the rectangular confines of the tubular construction 50, the latter is covered by a flexible housing or shroud 60, which can be made of rubber or corresponding pliant, elastic material. This shroud or enclosure extends above the water guard 27 and partially around the forward and rearward hollow tubes 51, 52, being suitably attached thereto by screws 61 or the like, the shroud terminating in depending skirt portions 62 spaced a short distance above the pavement surface S. The ends of the shroud or enclosure are secured by clamps 63 to vertical suction tubes 64 disposed centrally of the end tubes 53 and welded to the attachment rings 56 secured to the conical tubes or nipples 57 attached to the central portions of the end tubes. Thus, the enclosure 60 insures that ambient air can only enter the confines of the rectangular tube structure 50 by flowing inwardly and rearwardly from the region forwardly of the front tube member 51 toward its slot 54, forwardly from externally of the rear tube 52 toward its slot 54, and inwardly from the exterior of the end tubes 53 toward their slots 54.

The vertical suction tubes or riser pipes 64 at the ends of the pickup apparatus are each connected through a flexible connector 65 to a vacuum tube 66, attached through a flexible connector 67 to a connection 68 secured to the separator tank 34 and disposed tangentially thereof, such that the slurry and air is drawn into the upper end portions 340 of the separating tank. The tangential arrangement of the connections 68 with the tank causes the mixture of air, water and cuttings to spin around the curved wall of the cylindrical tank 34, effecting separation of some of the components of the mix, with the air being disposed in the upper part of the tank and the slurry of water and cuttings dropping to the lower portion of the tank 34. tqnk; of

In operation of the apparatus, the slurry valve 43 is closed initially, the engine 41 for driving the centrifugal pump 40 being at rest. The engine 38 is started to operate the displacement pump 35 to create a vacuum or suction in the separating tank 34 and the vacuum tubes 64 and 68, as well as in the rectangular tubular vacuum device 50. As the apparatus is operated by moving the vehicle forwardly of the pavement surface S, with the cutters 16 rotating, water is being pumped into the manifold 25 and discharged into the cylindrical water guard 27, the cutters being rotated in the direction of the arrow 70 (FIG. 4), while suction is being imposed on the rectangular tubular device 50 by the positive displacement pump 35. The slurry of cuttings and water are disposed essentially within the confines of the rectangular tube 50. Air is drawn from the regions externally of the tube structure 50. that is, from the region in advance of the forward tube 51. behind the rear tube 52, and outwardly of the and tubes 53, in an inward direction while the slurry is being drawn through the tube slots 54 to their interiors, the air also flowing toward these slots and assisting in raising the slurry off the pavement surface, thereby insuring that the water and. cuttings mixture will pass through the slots into the tubular device 50, and then through the vacuum tubes 64 and 68 into the separating tank 34. In the separating tank, the tangential discharge of the air, water and cuttings mixture effects separation of the air from the slurry, which the pump exhausts through the discharge line 37 to the atmosphere, the slurry dropping to the bottom of the tank. When the tank becomes about half filled with slurry, which, for example, might occur in approximately l0 to minutes of operation of the cutting apparatus under normal cutting conditions, the engine 41 is started and the shutoff valve 43 opened, so that the slurry is then pumped by the centrifugal pump 40 through the discharge line 44 into the settling tank 45 of the adjacent standing tank truck T, the cuttings settling to the lower part of the settling tank and the relatively clean water overflowing through the weir (not specifically shown) at the upper portion of the dividing partition 47 into the forward compartment 46, where the relatively clean water can be pumped through the line 23 into the water inlet 24 of the apparatus, being conducted into the manifold 25 for discharge through the nozzles or outlets 26 onto the cutters 16 once again.

The flow of air from the region adjacent and externally of the tubular pickup device 50 toward the inlets 54 of the pickup devices produces turbulence and its mixture with the slurry, as well as more intimate mixture of the cuttings and the water, so that a more efficient pickup of the cuttings and water from the pavement surface s is effected. Actual operations of the apparatus have demonstrated that more than 95 percent of the water and cuttings have been picked up, leaving the pavement surface comparatively free of cuttings and excess water. The pavement is left in a damp condition, but its surface S dries readily. Adjacent traffic lanes are not flooded with water and with water and cuttings slurry, as in the prior devices, nor is any significant quantity of cuttings left on the cut roadway surface which would tend to plug or clog the grooves 18 produced by the cutters, and also result in a dust hazard when the pavement surfaces dries. Accordingly, the surface behind the vacuumed work region is left in a clean, safe condition.

After the separating tank 34 has been emptied of slurry by the centrifugal pump 40, the valve 43 in the suction line 42 is closed and the engine 41 stopped. After the settling tank por tion 45 of the tank truck T has substantially filled with cuttings, the tank truck can be driven to a suitable point for disposal of the cuttings.

lclaim:

1. ln pavement-cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavementcutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means comprising tubular members disposed forwardly and rearwardly of said cutting means and adjacent thereto, said tubular members having bottom openings through which flushing fluid and cuttings ate Withdrawn from the region of operation of said cutting means; means supporting said tubular members a short distance above the pavement surface, said suction means being open in advance of said forward tubular member and rearwardly of said rearward tubular member to allow ambient air to be drawn at the pavement surface from regions forwardly and rearwardly of said tubular members and aid in lifting cuttings and flushing fluid from the pavement surface to said bottom openings.

2. ln apparatus as defined in claim 1; a separating tank connected to said suction means, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means.

3. ln apparatus as defined in claim 1; a separating tank connected to said suction means, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means; and means for withdrawing a slurry of cuttings and flushing fluid from the bottom of said tank.

4. ln apparatus as defined in claim 1; a generally cylindrical separating tank; a vacuum tube connected to said suction means and to said tank, said vacuum tube discharging air and a slurry of cuttings and flushing fluid tangentially into said tank to effect separation between the slurry and air, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said vacuum tube and suction means.

5. ln apparatus as defined in claim 1; a separating tank connected to said suction means, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing fluid discharging means.

6. ln pavement-cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavementcutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means comprising tubular members disposed forwardly and rearwardly of and adjacent to said cutting means, said tubular members having bottom openings through which flushing fluid and cuttings are withdrawn from the region of operation of said cutting means; said suction means further comprising tubular members at opposite ends of said cutting means, all of said tubular members being supported a slight distance above the pavement surface and having bottom openings through which flushing fluid, cuttings and ambient air can pass to the interior of said tubular members.

7. ln pavement cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavementcutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means adjacent to said cutting means for withdrawing flushing fluid and cuttings from the region of operation of said cutting means; said cutting means being elongate; said suction means including hollow side tubes located lengthwise of and forwardly and rearwardly of said cutting means and further including hollow end tubes at opposite ends of said cutting means, means supporting said side and and tubes a short distance above the pavement surface, said side and end tubes having bottom openings through which flushing fluid, cuttings and ambient air can pass to the interior of said tubes.

8, ln apparatus as defined in claim 7; and means providing an enclosure across said side tubes to confine ambient airflow from regions forwardly and rearwardly of said side tubes through the spaces between the bottoms of said side tubes and the pavement surface and to prevent substantial inward flow of air between said side tubes into said bottom openings.

9. ln pavement-cutting apparatus: support means adapted to transverse the pavement surface to be cut; rotatable pavement-cutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means adjacent to said cutting means for withdrawing flushing fluid and cuttings from the region of operation of said cutting means; said suction means including a rectangular tubular structure comprising side tubes located lengthwise of and forwardly and rearwardly of said cutting means and end tubes secured to said side tubes and located at opposite ends of said cutting means, means supporting said w bular structure a sort distance above the pavement surface, said side and end tubes having bottom openings through which flushing fluid, cuttings and ambient air can pass to the interior of said tubes.

10. in apparatus as defined in claim 9; said tubular structure being inclined in an upward and forward direction relative to the pavement surface.

11. In apparatus as defined in claim 9; and means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of said side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bot tom openings.

12. In apparatus as defined in claim 9; means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of therein side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bottom openings; a separating tank connected to said suction means, a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means; a second tank, means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing fluid discharging means.

13. In pavement-cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavement-cutting means carried by the support means to cut the pavement surface; means for discharging a flushing liquid upon the pavement surface at the region of operation by said cutting means on the pavement surface to flush cuttings from such region; a generally rectangular tubular structure comprising side tubes located lengthwise of and forwardly and rearwardly of said cutting means and end tubes communicating with said side tubes and located at opposite ends of said cutting means; means supporting said tubular structure a short distance above the pavement surface; said side and end tubes having bottom openings through which flushing liquid, cuttings and ambient air can pass into said tubes; a separating tank; a vacuum tube connected to one of said tubes and to said tank; and a vacuum pump connected to said tank to discharge air therefrom and to create suction in said tank, vacuum tube and tubular structure.

14. In apparatus as defined in claim 13; said vacuum tube being connected to one of said end tubes, and another vacuum tube connected to said other of said end tubes and to said tank.

15. In apparatus as defined in claim 13; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes and to said tank; said vacuum tubes being connected to the upper end portions of said tank to discharge air and a slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry and air; said vacuum pump being connected to the upper midportion of said tank.

16. in apparatus as defined in claim 13; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes and to said tank; said vacuum tubes being connected to the upper end portions of said tank to discharge air and a slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry of said tank; and means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said tank.

17. In apparatus as defined in claim 13; and means for withdrawing a slurry of cuttings and flushing liquid from said tank.

18. ln apparatus as defined in claim 13; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes and to said tank; said vacuum tubes being connected to the upper end portions of said tank to discharge air and a slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry and air; said vacuum pump being connected to the upper midportion of said tank; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing liquid discharging means.

19. in apparatus as defined in claim 13; means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of said side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bottom openings; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom ofsaid separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing liquid discharging means.

20. in apparatus as defined in claim 13; means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of said side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bot tom openings; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing liquid discharging means; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes ad to said separating tank; said vacuum tubes bcing connected to the upper end portions of said tank to discharge air and the slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry and air; said vacuum pump being connected to the upper midportion of said tank.

UNITED SJTA'JIJSS IA'UBNL OFFICE E I -\'r\' r'wu 1 r\' n CLRLlLlCAllu 01* (,ORRLCUON 3,608,968 Dated September 28, 1971" THEODOIfiB BURNETT Patent No.

I lnvcntor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as ehown below:

Column 5, line 55 61am line 10 "are" should be Cslumn 7 line 14, "therein" should be "said- Column 8, line S, cancel "of said tank" and substitute --and air--; line 5, before "and" insert --sa1d vacuum connected to the upper midportion of said tank;--,

pump being line 53, 'ad" should be --and--.

Signed and sealed this 21st day of March 1972.

(SEAL) Attest! EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of 'Patents 

1. In pavement-cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavementcutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means comprising tubular members disposed forwardly and rearwardly of said cutting means and adjacent thereto, said tubular members having bottom openings through which flushing fluid and cuttings are withdrawn from the region of operation of said cutting means; means supporting said tubular members a short distance above the pavement surface, said suction means being open in advance of said forward tubular member and rearwardly of said rearward tubular member to allow ambient air to be drawn at the pavement surface from regions forwardly and rearwardly of said tubular members and aid in lifting cuttings and flushing fluid from the pavement surface to said bottom openings.
 2. In apparatus as defined in claim 1; a separating tank connected to said suction means, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means.
 3. In apparatus as defined in claim 1; a separating tank connected to said suction means, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means; and means for withdrawing a slurry of cuttings and flushing fluid from the bottom of said tank.
 4. In apparatus as defined in claim 1; a generally cylindrical separating tank; a vacuum tube connected to said suction means and to said tank, said vacuum tube discharging air and a slurry of cuttings and flushing fluid tangentially into said tank to effect separation between the slurry and air, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said vacuum tube and suction means.
 5. In apparatus as defined in claim 1; a separating tank connected to said suction means, and a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing fluid discharging means.
 6. In pavement-cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavement-cutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means comprising tubular members disposed forwardly and rearwardly of and adjacent to said cutting means, said tubular members having bottom openings through which flushing fluid and cuttings are withdrawn from the region of operation of said cutting means; said suction means furTher comprising tubular members at opposite ends of said cutting means, all of said tubular members being supported a slight distance above the pavement surface and having bottom openings through which flushing fluid, cuttings and ambient air can pass to the interior of said tubular members.
 7. In pavement cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavement-cutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means adjacent to said cutting means for withdrawing flushing fluid and cuttings from the region of operation of said cutting means; said cutting means being elongate; said suction means including hollow side tubes located lengthwise of and forwardly and rearwardly of said cutting means and further including hollow end tubes at opposite ends of said cutting means, means supporting said side and end tubes a short distance above the pavement surface, said side and end tubes having bottom openings through which flushing fluid, cuttings and ambient air can pass to the interior of said tubes.
 8. In apparatus as defined in claim 7; and means providing an enclosure across said side tubes to confine ambient airflow from regions forwardly and rearwardly of said side tubes through the spaces between the bottoms of said side tubes and the pavement surface and to prevent substantial inward flow of air between said side tubes into said bottom openings.
 9. In pavement-cutting apparatus: support means adapted to transverse the pavement surface to be cut; rotatable pavement-cutting means carried by the support means to cut the pavement surface; means for discharging a flushing fluid upon the pavement surface at the region of operation of said cutting means on the pavement surface to flush cuttings from such region; and suction means adjacent to said cutting means for withdrawing flushing fluid and cuttings from the region of operation of said cutting means; said suction means including a rectangular tubular structure comprising side tubes located lengthwise of and forwardly and rearwardly of said cutting means and end tubes secured to said side tubes and located at opposite ends of said cutting means, means supporting said tubular structure a sort distance above the pavement surface, said side and end tubes having bottom openings through which flushing fluid, cuttings and ambient air can pass to the interior of said tubes.
 10. In apparatus as defined in claim 9; said tubular structure being inclined in an upward and forward direction relative to the pavement surface.
 11. In apparatus as defined in claim 9; and means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of said side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bottom openings.
 12. In apparatus as defined in claim 9; means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of said side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bottom openings; a separating tank connected to said suction means, a vacuum pump connected to said tank to discharge air from said tank and to create suction therein and in said suction means; a second take; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing fluid discharging means.
 13. In pavement-cutting apparatus: support means adapted to traverse the pavement surface to be cut; rotatable pavement-cutting means carried by the support means to cut the pavement surface; means for discharging a flushing liquid upon the pavement surface at the region of operation by said cutting means on the pavement surface to flush cuttings from such region; a generally rectangular tubular structure comprising side tubes located lengthwise of and forwardly and rearwardly of said cutting means and end tubes communicating with said side tubes and located at opposite ends of said cutting means; means supporting said tubular structure a short distance above the pavement surface; said side and end tubes having bottom openings through which flushing liquid, cuttings and ambient air can pass into said tubes; a separating tank; a vacuum tube connected to one of said tubes and to said tank; and a vacuum pump connected to said tank to discharge air therefrom and to create suction in said tank, vacuum tube and tubular structure.
 14. In apparatus as defined in claim 13; said vacuum tube being connected to one of said end tubes, and another vacuum tube connected to said other of said end tubes and to said tank.
 15. In apparatus as defined in claim 13; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes and to said tank; said vacuum tubes being connected to the upper end portions of said tank to discharge air and a slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry and air; said vacuum pump being connected to the upper midportion of said tank.
 16. In apparatus as defined in claim 13; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes and to said tank; said vacuum tubes being connected to the upper end portions of said tank to discharge air and a slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry and air; said vacuum pump being connected to the upper midportion of said tank; and means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said tank.
 17. In apparatus as defined in claim 13; and means for withdrawing a slurry of cuttings and flushing liquid from said tank.
 18. In apparatus as defined in claim 13; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes and to said tank; said vacuum tubes being connected to the upper end portions of said tank to discharge air and a slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry and air; said vacuum pump being connected to the upper midportion of said tank; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing liquid discharging means.
 19. In apparatus as defined in claim 13; means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of said side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bottom openings; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting fluShing liquid from said second tank to said flushing liquid discharging means.
 20. In apparatus as defined in claim 13; means providing an enclosure over said rectangular tubular structure to confine flow of ambient air from regions outwardly of said structure through the spaces between the bottoms of said side and end tubes and the pavement surface and to prevent substantial flow of air downwardly within said structure and into said bottom openings; a second tank; means for withdrawing a slurry of cuttings and flushing liquid from the bottom of said separating tank and delivering the slurry into said second tank for separation of said cuttings and flushing liquid in said second tank; and means for conducting flushing liquid from said second tank to said flushing liquid discharging means; said separating tank being a generally cylindrical horizontal tank; said vacuum tube being connected to one of said end tubes; another vacuum tube connected to said other of said end tubes and to said separating tank; said vacuum tubes being connected to the upper end portions of said tank to discharge air and the slurry of cuttings and flushing liquid tangentially into said tank to effect separation between the slurry and air; said vacuum pump being connected to the upper midportion of said tank. 